Electroresponsive device.



E. A. BUGKMAN.

ELEGTRORESPONSIVE DEVICE.

APPLICATION FILED JULY 1, 1907.

905,495 Patented Dec. 1, 1908.

n4: name's PETERS cu., WASHINGTON, u. c.

UNITED STATES PATENT OFFICE.

EDWARD A. BUOKMAN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO HARRY L. FELIO, OF CHICAGO, ILLINOIS.

E LE GTRORESPONSIVE DEVICE Specification of Letters Patent.

Patented Dec. 1, 1908.

Application filed July 1, 1907. Serial No. 381,720.

To all whom it may concern:

Be it known that I, EDWARD A. BUOKMAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electroresponsive Devices, of which the following is a specification.

My invention relates to improvements in electro responsive devices, and more particularly to electric bells.

One of the salient objects of my invention is to provide a bell structure which is simple, cheap, electrically advantageous in construction and eflicient in operation.

A further object of my invention is to provide an improved electro-magnet structure for electro responsive devices such as electric bells. And other and further objects of my invention will become apparent to those skilled in the art from the following description, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a plan view of the bell movewent, the bell proper or gong being detached. Fig. 2 is a cross section on line 2-2 of Fig. 1. Fig. 3 is a fragmentary section on line 33 of Fig. 1. Figs. 4 and 5 are longitudinal and transverse sectional details showing the construction of the electro-magnet. Fig. 6 is a perspective of a magnet pole member. Fig. 7 is a detail showing an exterior wiring terminal in section.

Throughout the difierentviews like numerals of reference refer always to like parts.

In the drawings, wherein my improvements are shown as embodied in an electro responsive device in the form of a circuit breaking bell, 10 indicates the metallic baseframe, of the usual circular form, having secured therein an insulating base 11, said base-frame comprising a rim 12 extending above the base, recessed in its edge, as at 12,

and providing projecting lugs 13 for attachment to a wall.

1% indicates an arm extending upward from rim 12 to position above the center of the base 11, to carry the gong 15, from which preferably projects inwardly, at a suitable peripheral point, a pin 16 with which the striker of the mechanism may coact.

The electro-magnet preferably employed in my construction is peculiar in structure,

and I have found, highly efiicient in operation. Said electro-magnet, generally indicated at 28, preferably comprises a coil having a core of peculiar construction spirally lamina-ted, and laminated pole pieces in effective magnetic contact with said core, bent (so to approach each other in a common plane parallel with the core. In the specific construction shown (see particularly Fig. 6) 19 indicates in general a pole piece, comprising a face member 20 and an end member 21, made in a single piece of folded sheet metal susceptible of magnetic effect, said members standing at right angles to each other. One leaf of the metal is continued downwardly from the free end of the end member 21 to form a foot 22 and an interposed connection 23 flexible in direction transverse to the end member 21. Two such pole structures 19 are provided, as shown in Fig. 1, in opposing relation such that the face members 20 lie in a common plane in somewhat separated relation to each other.

Between the pole members 19 are mounted the core and coils of the electro magnet. The electro magnet core I prefer shall be composed of a strip or ribbon of suitable metal wound of uniform width spirally around a central support in any suitable number of convolutions, the successive convolutions being preferably slightly separated from each other, as by a coating of paint, or varnish, covering one or both sides of the strip. In the construction shown the supporting member of the core is a bolt 25, extending through apertures 26, provided therefor in the end members 21 of the pole structures 19, said bolt being provided with a suitable securing nut 26 at one end. The strip 2'? is wound upon the support 25 so that its ends are true and flat, and at said ends it makes intimate magnetic contact with the end members 21 and the pole pieces, through the action of the tension nut 26, which is adjusted to draw the end members tightly against the volute strip. The coil 30 of the electro magnet is wound. upon the core thus provided in the usual manner. The magnet thus constituted is mounted so that its long alining polar surfaces approximately follow a diameter of the base.

The movable mechanism of the gong comprises a striker or head 30 mounted upon a long spring arm 31, which extends across the frame in approximate parallelism to the pole faces 20, and at its remote end is se- 110 cured in a suitable standard 32 mounted on the insulating base 11. The armature 33 preferably comprises a doubled strip of sheet metal embracing between its leaves the flat spring 31, and also the end of a contact member 34, which bends back over the outer face of the armature for contact with a stationary contact member 35, suitably mounted in the insulating base. The striker 30 plays in the edge recess 12 of the frame rim 12 for contact with projection 16 of the gong.

For convenience in installation the electric Wiring of the responsive device is so arranged that the same screws or other holding devices used to secure the frame upon the wall or supporting structure, are utilized for the attachment of the exterior winding and its connection with the internal wiring. To this end each of the lugs 13, heretofore mentioned, is provided with an enlarged, preferably tapering aperture 36, in which is arranged a bushing of insulating material, such as hard rubber, as indicated at 37, Fig. 7. Such hard rubber bushing 37 is arranged to project slightly above the lug 13 and is centrally apertured to receive a screw.

Each terminal wire of the electro-responsive device is run through an appropriate aperture in rim 12 and is soldered or otherwise secured to a washer 39 placed upon the bushing 37, so that a screw or other fastening device 40, aassing through the washer 39, bushing 37 and into the wall or support, as indicated in Fig. 7, may secure the bell in place and at the same time hold in contact upon the washer 37, the exterior wiring fragmentarily indicated at 41 in Fig. 7.

The interior wiring of the device is arranged in the customary manner, one lug 13 having connection with the coil 23, the opposite end of which is connected with the support 32, while the stationary contact 35 has connection with the remaining lug 13 of the appliance.

In the operation of the bell I find that electrically the responsive device described is highly efficient, as the volute core affords a large surface for the residence of magnetism, while the angular pole members provide extended polar surfaces approximately diametrically traversing the closed area of the bell for coaction with the extended laminated armature, which by reason of its construction and the length of spring afforded, is very sensitive. I have found, furthermore, that the arrangement described whereby the striker coacts with the pin or projection carried by the gong, is very efiective,

as it insures a clean, clear blow of the striker upon the sounding member, and conduces to a free, rapid recoil of the movable element to circuit closing position.

WVhile I have herein described in some detail an embodiment of my invention, which I have found to be practical and advantageous, it will be apparent to those skilled in the art that numerous changes in the specific construction might be made without departure from the spirit and scope of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent, of the United States, is:

1. In an electro responsive device, a magnet having a core comprising a continuous advancing, spirally wound strip of sheet ieta-l.

2. In an electro responsive device,a magnet having a core'comprising a continuous strip of metal wound spirally advancing, with its convolutions terminating in a plane transverse to the axis of the core, a pole member making contact flat across the end of said spirally wound core, and a coil wound upon said core.

3. In an electro responsive device, an electro magnet composed of a volute core of sheet metal spirallyadvancingly wound terminating at its ends in planes at right angles to the axis of the core, pole pieces comprising end parts extending transversely across the core and making fiat contact with the ends thereof, and pole pieces at right angles to said end pieces converging toward but separated from each other, in a plane parallel to the core, and a coil wound upon said core.

Al. In an electro responsive device, an electro magnet comprising a spirally advancing laminated core, laminated pole pieces secured to said core and a coil wound upon the core.

5. In an electro responsive device, a magnet comprising a central connecting member, a metal strip wound upon said connecting member to constitute the core of the magnet, a pole member extending transversely across the ends of said strips, and maintained in magnetic connection with said ends by the central connection member, and a coil wound upon the core.

In testimony whereof I hereunto set my hand in the presence oftwo witnesses.

EDIVARD A. BUGKMAN.

In the presence of Foniin BAIN, MARY F. ALLEN. 

